[PATCH v2] PCI: Disable Samsung SM951/PM951 NVMe before FLR

From: Robert Straw
Date: Fri Apr 30 2021 - 19:01:31 EST


The SM951/PM951, when used in conjunction with the vfio-pci driver and
passed to a KVM guest, can exhibit the fatal state addressed by the
existing `nvme_disable_and_flr` quirk. If the guest cleanly shuts down
the SSD, and vfio-pci attempts an FLR to the device while it is in this
state, the nvme driver will fail when it attempts to bind to the device
after the FLR due to the frozen config area, e.g:

nvme nvme2: frozen state error detected, reset controller
nvme nvme2: Removing after probe failure status: -12

By including this older model (Samsung 950 PRO) of the controller in the
existing quirk: the device is able to be cleanly reset after being used
by a KVM guest.

Signed-off-by: Robert Straw <drbawb@xxxxxxxxxxxxxxx>
---
changes in v2:
- update subject to match style of ffb0863426eb

drivers/pci/quirks.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 653660e3b..e339ca238 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3920,6 +3920,7 @@ static const struct pci_dev_reset_methods pci_dev_reset_methods[] = {
reset_ivb_igd },
{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IVB_M2_VGA,
reset_ivb_igd },
+ { PCI_VENDOR_ID_SAMSUNG, 0xa802, nvme_disable_and_flr },
{ PCI_VENDOR_ID_SAMSUNG, 0xa804, nvme_disable_and_flr },
{ PCI_VENDOR_ID_INTEL, 0x0953, delay_250ms_after_flr },
{ PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID,
--
2.31.1